RESUMEN
The effect of diets enriched with oat or wheat bran (prepared by the addition of 300 g of each fiber to 1000 g of the regular diet), given for 8 weeks, on the mucosal height of the colon and cecum was investigated. Newly weaned (21 days old) and aged (12 months old) male Wistar rats were used in this study. As compared to controls, diets enriched with wheat bran provoked a significant increase in the mucosal height, whereas oat bran did not cause any effect. In newly weaned rats (21 days old), wheat bran increased the mucosal height (mum) in the cecum by 20 per cent (mean + SEM for 8 rats; 169.1 + 5.2 and 202.9 + 8.0 for control and wheat bran, respectively) and in the colon (218.8 + 7.2 and 264.5 + 18.8 for control and wheat bran, respectively). A similar effect was observed in aged rats (12 months old), with an increase of 15 per cent in the mucosal height (mum) of the cecum (mean + SEM of 8 rats; 193.2 + 8.6 and 223.7 + 8.3 for control and wheat bran, respectively) and of 17 per cent in the colon (300.4 + 9.2 and 352.2 + 15.9 for control and wheat bran, respectively).